/*
 * $URL: https://dnsprobe.googlecode.com/svn/trunk/dnsprobe/src/dnsprobe/resolver/NameserverPool.java $
 * 
 * Copyright (c) 2009, Anonymous
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Anonymous nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY ANONYMOUS ''AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL ANONYMOUS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 */

package dnsprobe.resolver;

import java.util.ArrayList;
import java.util.List;


/**
 * objektpool fuer nameserver-objekte, an denen sich die workerthreads 
 * bedienen koennen. ein nameserverpool stellt immer eine menge an objekten, 
 * mindestens 5, fuer einen bestimmten nameserver bereit, der im konstruktor 
 * des nameserverpools uebergeben wird.
 * 
 * TODO anzahl der maximalen objekte limitieren
 * 
 * @author BerndBernhardson
 * @author anon004
 * @author snoop
 * @version $Id: NameserverPool.java 99 2009-07-01 15:00:03Z bernhardson@gmx.net $
 *
 */
@Deprecated
public class NameserverPool
{
	private final String nameserver;
	
	private final List<Nameserver> pool;
	
	private int minCount;
	private int maxCount;
	
	public NameserverPool(final String nameserver)
	{
		this.nameserver = nameserver;
		
		this.pool = new ArrayList<Nameserver>();
		
		this.minCount = 5;
		this.maxCount = 20;
		
		init();
	}
	
	private Nameserver newNameserver()
	{
		return new Nameserver(nameserver);
	}
	
	private void init()
	{
		for(int i = 0; i < minCount; i++)
		{
			pool.add(newNameserver());
		}
	}
	
	public synchronized Nameserver acquire()
	{
		Nameserver object;
		
		if(pool.size() > 0)
		{
			object = pool.get(pool.size()-1);
			
			pool.remove(pool.size()-1);
		}
		else
		{
			object = newNameserver();
		}
		
		return object;
	}
	
	public synchronized void release(final Nameserver object)
	{
		if(!pool.contains(object))
		{
			pool.add(object);
		}
	}
	
	public synchronized void cleanup()
	{
		if(pool.size() < maxCount)
		{
			return;
		}
		
		final int toDelete;
		
		toDelete = pool.size()-1 - maxCount;
		
		for(int i = 0; i < toDelete; i++)
		{
			pool.remove(pool.size()-1);
		}
	}
}
